Fuel cell system

A fuel cell system comprising:

• a fuel supplier that is a linear solenoid valve controllable at an intermediate opening degree;
• a pressure sensor at an inlet of a fuel cell;
• a current quick cut-off circuit in a fuel gas system, wherein the current quick cut-off circuit includes a discharge path configured to dissipate current supplied to the fuel supplier thereby accelerating a current cut-off response;
• and
• a control unit, wherein:
• the control unit determines whether a pressure measured by the pressure sensor exceeds a predetermined threshold value;
• when the pressure measured by the pressure sensor exceeds the predetermined threshold value, the control unit turns on a failure determination preliminary flag based on that it is highly likely that a failure determination is made, and switches a drive circuit of the fuel supplier to the current quick cut-off circuit;
• when the pressure measured by the pressure sensor is equal to or less than the predetermined threshold value, the control unit does not switch the drive circuit of the fuel supplier to the current quick cut-off circuit;
• after the drive circuit of the fuel supplier is switched to the current quick cut-off circuit, the control unit determines whether the pressure measured by the pressure sensor exceeds the predetermined threshold value;
• and
• when the pressure measured by the pressure sensor exceeds the predetermined threshold value, the control unit makes the failure determination, and issues a command to close the linear solenoid valve.